Fire extinguisher wheel cap



1950 c. K. HUTHSING, SR 2,948,342

FIRE EXTINGUISHER WHEEL CAP Filed Sept. 9, 1955 FIG. 1

INVENTOR. CHARLES K. HUTH5\NG,SR. m a my ATTO NEYS United States Patent Qfii ce I 2,948,342 Patented Aug 9, 1960 FIRE EXTlNGUISI-IER WHEEL CAP Charles K. liuthsing, Sr., Culver City, Calif., assignor to General Pacific Corporation, a corporation of California Filed Sept. 9-, 1955, Ser. No. 533,288

1 Claim. .(Cl. 169-1) Wheel caps are a conventional component in certain types of fire extinguisher designs. For many years, in accordance with industry specifications, certain standard structural elements have been embodied in most wheel cap constructions. Such constructions usually include an annular base or mounting member, a ring handle, and 'a plurality of uprights interconnecting the ring handle to the mounting member. In present day designs, the uprights usually comprise straight members, which extend upwardly and outwardly from the base member to connect with the ring handle, the latter having a larger diameter than the base member.

The wheel cap has several functions in connection with the overall construction and operation of the fire extinguisher. First, the base member of the cap must serve as an effective closure, to seal off the contents of the tank from the atmosphere. Second, the ring handle of the cap must serve as a gripping member, whereby the extinguisher may be lifted and carried from one location to another. Thirdly, the cap as a whole must function as a supporting and protective member, in the event that the extinguisher is positioned so as to have its full weight acting downwardly on the cap or in the event that the extinguisher is dropped from some distance or otherwise abused in a manner in which the cap would be subject to impact. As most of these functions relate to safety requirements, the industry has set up a rather rigid set of structural limitations in order that the cap be accepted according to certain safety codes. As a consequence, the standard structure (as described above) has been used consistently by most manufacturers to conform with these limitations.

Even in conforming with these specifications, it has been realized that a stronger cap is desirable in certain applications, particularly where the cap may be subject to rough handling under hazardous conditions. It has, however, been a difficult problem to properly design a cap of improved strength without departing from the industry specifications or materially increasing the manufacturing costs.

It is, therefore, an object of the present invention to provide an improved fire extinguisher wheel cap, which will still meet with the rigid specifications of the industry and yet provide a substantially stronger construction.

Another object is to provide an improved fire extinguisher wheel cap which does not use appreciably more material than the present daywheel cap designs, and

which because of its structure may be manufactured at substantially the same cost as the conventional cap.

These and other objects of the present invention have I been achieved by providing an improved wheel cap for a fire extinguisher incorporating generally right angularly shaped uprights rather than the straight members used asuprights' in previous designs. By using such a construction it is possible to have the uprights directly share a large proportion of the load carrying capacity of the cap, in the event the extinguisher is in an inverted position, rather than have the ring handle take the entire load. as with .the conventional construction; It is also possible by the use of these improved uprights to direct a portion of the load towards the base member at a closer radial distance from its axis so that the tendency of shearing the uprights themselves or of breaking them away from the base member is significantly decreased.

A better understanding of the present invention will be had by reference to the drawings, illustrating a preferred embodiment, in which:

Figure 1 is-a perspective view of the improved wheel cap according to the present invention mounted on the upper portion of a fire extinguisher tank;

Figure 2 is a sectional view of the wheel cap of Figure 1 taken in the direction of the arrows 2-2;

, Figure 3 is an enlarged perspective view of the encircled portion .3 of Figure l; and

"Figure 4 is a cross sectional view of one of theuprights taken in the direction of 4-4 of Figure 2.

In Figure 1, there is generally shown a wheel cap 10 according to the present invention mounted on the collar of the fire extinguisher 11.

As shown more clearly in the view of Figure 2, the extinguisher includes an annular base member 12 having side walls 13 terminating at one end in a convex closure 14. The sidewalls 13 are provided with an inner' threading 15 for mounting the cap 10 and securing it tothe extinguisher 11. The side walls 13 of the base member 12 are additionally provided with an inner annular recess 16 adapted to receive an annular gasket 17. A suitablepressure relief means may be provided in thef form of an opening 18 extending laterally through the side walls 13. The overall structure and details of thebasemember .12 are not deemed to be part of the present invention.

A ring handle 19 is disposed a given vertical distance above the end closure 14 and is positioned in co-axial relationship with the base member 12. The ring member 19 is conventionally designed to have an appreciably greater inner diameter than the outer diameter of the annular base member. Such a construction facilitates the handling and gripping of the wheel cap 10 by an operator, and it additionally provides a more secure supporting structure in the event the extinguisher 11 is rested in an inverted position on the wheel cap.

A primary feature of the present invention resides in the provision of a plurality of right angular uprights generally designated by the numeral 20, interconnecting the ring handle .19 with the end closure 14 of the base member 12. Each upright 20 includes a horizontal portion 21 extending radially inward a given distance. The upper surface of the horizontal portion 21 is disposed in a plane formed by the uppermost peripheral points of the ring handle. In consequence, it the wheel cap 10 is inverted, together with an attached extinguisher 11, and rested on a flat surface; the weight of the extinguisher 11 will be distributed over the horizontal portions 21 of the uprights 20, as Well as over the uppermost peripheral portion of the ring 19. It will also be apparent in this instance that the force distribution, representing the weight of the extinguisher and the wheel cap, will :be such as to be centered intermediate of the ring handle 19 and the radially innermost end of the horizontal portion 21.

The upright 20 also includes a generally vertical portion 22, integrally connected with the horizontal portion 21, and extending downwardly and slightly inwardly to connect with the outer edge of the end closure .14 at 23, as shown more clearly in the View of Figure 3.

As also shown in the view of Figure 3, the upright 2% is designed with a curved contour for the purpose of additional strength. In this regard, the upright 20 is also provided with an outer rib 24 which generally follows the contour of the vertical portion 22 and the horizontal portion 21 to terminate and merge into the base member 12 and the ring handle 19, respectively. The rib member 24 is more clearly shown in the view of Figure 4, wherein a conventional cross section is shown for the upright 21'? as including two arcuate sections 25.

The importance of the present invention is more clearly understood when considered in relation to certain structural limitations placed upon the design of the wheel cap it according to industry codes. For safety purposes, the industry requires that the ring handle 19 and uprights 2t, withstand a crushing load between flat surfaces of at least 3020 pounds. In addition, a further limitation is imposed on the design by requiring that the ring handle 19hr; disposed a given vertical distance of at least one inch above the enclosure 14 and that it also have a minimum outer diameter of and inches. In the past, conventional wheel caps have included sloping uprights extending in a straight line from the end closure to the ring handle. Such uprights, although complying with the minimum requirements have not been designed so as to provide extra strength for unusual handling conditions. 0n the other hand, the uprights 20 of the present invention, as well as complying with the industry dimensional restrictions, significantly increase the strength of the uprights under a compressional load. in this regard, actual tests have proved that the uprights will withstand at least 5000 pounds under a compressional load.

This increased load carrying capacity of the improved wheel cap 1d results in part from the provision of the horizontal portion 21 of the upright 20, as described above, in combination with the provision of an integral, generally vertical portion 22. In addition, the rib 24 functions to give greater strength to the overall structure of the upright 2%). These combined structural features enable the uprights 20 to carry a considerable proportion of the load throughout an area appreciably radially closer to the point 23 where the upright connects into the end closure 14. Thus, the bending torque that may act to shear the upright 20* from the closure 14 is appreciably decreased because of the shorter leverage distance. In addition, it will be apparent that the up rights 20 as such carry a larger proportion of the load in compression rather than in shear as with the former designs. Thus, the uprights 20 may be subjected to substantially greater loads.

From the foregoing description, it will be evident that the improved Wheel cap structure of the present invention provides greatly increased strength without departing from the rigid design limitations imposed by the industry for safety purposes. Certain modifications and changes will appear to those skilled in the art with respect to the embodiment shown for illustrative purposes. The invention is not to be thought of, therefore, as limited to the particular details of the wheel cap design described and shown in the drawings.

What is claimed is:

A fire extinguisher wheel cap comprising: an annular base member having an upper end closure; a ring handle co-a-Xiai with and spaced above said end closure a given distance, said handle having an inner diameter greater than the outer diameter of said base member; a plurality of upright members rigidly connected between said end closure and said ring handle, each of said upright members including .a vertical portion radiused into and extending upwardly from said end closure and a horizontal portion extending radially outwardly from the upper end of said vertical portion to connect with said ring handle, said horizontal portion being radiused into the upper end of said vertical portion, and comprising an integral continuation of said vertical portion and said horizontal portion having an upper surface in a plane including the uppermost peripheral points of said ring handle References Cited in the file of this patent UNITED STATES PATENTS 649,160 Clarke May 8, 1900 inr 

